Certain imidazoline salts



United States Patent ()fiice 3,313,825 Patented Apr. 11, 1967 3,313,825 CERTAIN llVIIDAZOLINE SALTS Milton Rosenberg, Yonkers, Hyman W. Zussman, Scarsdale, and Robert Beaudoin, Mount Vernon, N.Y., assignors to Geigy Chemical Corporation, Ardsley, N.Y., a corporation of Delaware No Drawing. Original application July 25, 1961, Ser. No. 126,490, now Patent No. 3,210,312, dated Oct. 5, 1965. Divided and this application July 7, 1965, Ser. No. 478,786

8 Claims. (Cl. 260309.6)

This application is a divisional application of our copending application, Ser. No. 126,490, filed July 25, 1961, now Patent No. 3,210,312.

This invention relates to a process for preventing static charge from accumulating on resins, in particular on poly vinyl chloride resins or copolymers of vinyl chloride and vinyl esters. The invention is also concerned with novel anti-static agents and compositions thereof with polyvinyl chloride-type resins. The invention also relates to preventing static charge on resins of polystyrene.

The anti-static agents of the invention are imidazoline salts, formed by reacting (i) an organic base of the Formula I:

wherein R is an alkyl group preferably, an alkyl group having from 7 to 17 carbon atoms, or an alkenyl group preferably, an alkenyl group having at least 1 double bond and from 7 to 17 carbon atoms; the most preferred groups are alkyl having 11 carbon atoms, and

R is hydroxyalkyl, especially hydroxy(lower)alkyl, e.g.

hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, preferably hydroxyethyl,

with (ii) at least one of either a dibasic organic acid or hydroxy organic acid having at least one free carboxy group. Mixtures of salts may also be used. Specific acids are adipic, sebacic, isophthalic, tartaric, and mercaptosuccinic acid, but the preferred acids are adipic acid and sebacic acid. Acid salts as well as neutral salts are within the scope of the invention. Particularly valuable salts for anti-static purposes are di-[l-(B-hydroxyethyl)-2-undecylimidazoline] adipate, di-[1-(fi-hydroxyethyl)-2-undecylimidazoline] sebacate, di-[1 (fl-hydroxyethyl)-2-undecylimidazoline] isophthalate, di-[l-(p-hydroxyethyl)-2-undecylimidazoline] tartarate, and di-[l-(fi-hydroxyethyD- Z-undecylimidazoline]mercaptosuccinate.

It is Well known that imidazoline salts may be used for external application to polymers of vinylchloride and interpolymers of vinyl chloride and vinyl esters as well as other polymeric resins, e.g. polystyrene, which tend to accumulate static electricity. Nevertheless, the salts of dibasic organic acids or hydroxy organic acids having at least one carboxy group, formed from the compounds of the Formula I, are surprisingly more effective as antistatic agents than presently known salts of compounds of the Formula I such as l-(B-hydroxyethyl)-2-undecylimidazoline acetate.

Other resins may be protected against static charge accumulation. Such resins are e.-g. vinyl resins containing acrylonitrile, polyethylene, polypropylene, etc. The invention is also useful for preventing static build-up in paper, in inks, in protective coatings by simple incorporation of a small but effective amount of the desired antistatic agent in the substrate.

It is an object of the present invention to provide a method of stabilizing resins such as polystyrene, but preferably polyvinyl chloride or interpolymers of vinyl chlo ride and vinyl esters, against static charge accumulation by incorporating in said resins an effective quantity of an antistatic agent, which consists of a salt of an organic dibasic acid or hydroxy organic acid, having at least one carboxy group, of a compound of the Formula I. In particular, it is a preferred object of this invention to stabilize shaped articles of polyvinyl chloride resins or resins which are interpolymers of vinyl chloride or vinyl esters, especially phonograph records comprising said resins.

In addition to the anti-static agents, it is often desirable to incorporate other additives into the polyvinyl chloride resin. Such additives are heat stabilizers, lubricity agents, pigments or other coloring materials, etc. The heat stabilizer additive may be any suitable agent such as for example metallic salts of organic acids, i.e. cadmium, zinc, barium, lead stearates or mixtures thereof. Other stabilizers useful in polyvinyl chloride or polyvinyl acetate or in polystyrene resins may be employed. The heat stabilizer is usefully employed in an amount of from about 1% to 2% based on the weight of unstabilized resin.

The essence of the invention is not concerned with these additives, although a particular use for the shaped article may require one additive, rather than another, in varying quantities. The invention is founded on the remarkable discovery that the aforesaid novel salts are extremely effective anti-static agents, especially when compared with commercially used anti-static agents.

The following illustrate the invention, but by no means limit the scope thereof. In the examples, parts are by weight, and the relationship of parts by weight to parts by volume is as that of grams to cubic centimeters. Temperatures are in degrees centigrade.

Example 1 69 parts l-(fi-hydroxyethyl)-2-undecylimidazoline in a molten state is added to a mixture of 18.25 parts adipic acid in 87.25 parts of a 50% (weight) aqueous isopropanol solution and the resultant mixture is heated at 60 with gentle stirring for 5 minutes. It is heated at 69 for another 5 minutes and the amber liquid reaction mixture is allowed to cool to room temperature.

The di-[l-(B-hydroxyethyl)-2-undecylimidazoline] adipate is then added to a commercially available copolymer of vinyl chloride and vinyl acetate (Bakelite VYHH), said copolymer consisting of approximately 15% by weight of vinyl acetate and by weight of vinyl chloride, so that the resulting resin contains 1% by weight of this anti-static agent. The addition of the anti-static agent to the aforesaid copolyrner of vinyl chloride and vinyl acetate is effected by mixing the solution thereof at room temperature with said copolymer in the form of a powder. Thereafter, 1% by weight of barium-cadmium laurate (Advastab BC-12) is added as heat stabilizer in order to permit milling of the copolymer and anti-static agent mixture. Furthermore, 1% by weight of carbon black is also added before milling.

The milling of the foregoing polyvinyl chloride polyvinyl acetate resinous powder, mixed with the aforesaid additives, is carried out on a heated two-roller mill as follows: 309 parts of the mixture to be milled are placed upon the rollers, which are heated to 150 for a period of 5 minutes. The so-forrned sheet of resinous copolymer is sheeted from the mill, cooled and cut into approximately cm. squares. 130 parts of said squares are placed in a die and pressed at 132 with a charge is measured with an electrometer to yield numerical values convertible to volts static charge, thus giving an exact comparative value relative to the several phonograph records tested.

A corona grid charged with 8000 volts is used to create a field through which the phonograph record is passed, and the charge retained on the record surface is measured with the electrometer at intervals of 1 and minutes.

Table II shows the results of the foregoing test proce force of tons with a 4 square inch ram on a circular 1O dure.

TABLE II.STATIC VALUES OBSERVED FOR RESINS MILLED AT 150 FOR 5 MINUTES 0N ROLL MILL Total Static Charge Measured on the Surface of Phono graph Record 1% (\Vt.) di(1B- 1% (Wt) did-flhydroxyethyl-2- hydroxyethyl-2- Blank (no antiundecylimidazoundecylirnidazostatic agent)total line) Adipate line) Sebacate charge, volts total charge, volts total charge, volts Measurement of Total Charge at the End of 1 minute after charging 180 300 3, 000 Measurement of Total Charge at the End of 15 minutes after charging 0 120 3,000

die, having a 10 inch diameter, to produce a 10 inch diam- Example 3 eter black phonograph record. This record has very good anti-static properties.

Example 2 Other phonograph records comprising a major portion of a copolymer of vinyl chloride and vinyl acetate (Bakelite VYHH) are produced in the same manner as described in Example 1 with good anti-static properties and with 1% by weight (based on resin) of the following anti-static agents:

The anti-static agents are prepared in a manner analogous to that described in Example 1 with the proportions set forth in Table I.

A film of polystyrene is prepared with reduced surface charges by incorporating 0.5 by Weight of di-[l-(p-hydroxyethyl)-2-undecylimidazoline] adipate into the film in the following way: polystyrene pellets (Lustrex HF 662020, 206) are coated with 0.5% by weight of the anti-static compound in a volatile isopropanol solution which is removed by drying in an oven at The coated pellets are extruded to form a 3.5 mil film having reduced surface charge.

What is claimed is:

1. A salt of a member selected from the group consisting of:

(i) the imidazoline compound of the formula:

N-CH2 1'1. wherein:

R is a member selected from the group consisting TABLE I.FORMATION OF ANTI-STATIC AGENTS BY REACIING AN ORGANIC ACID WITH AN IMIDAZOLINE Reactants, Parts by Weight Salt Organic Acid Parts l-(Bhydroxyethyl) Parts Imidazoline Adipic 18. 25 Z-undecyl 69 Di-[l-(fl-hydr0xyethyl)-2-undecy1imidazoline] adipate. Sebacic 25. 28 do 69 D1-[1-(B-hydroxyethyl)-2 undeeylimidv azoline] sebacate. Isophthalic 20. 8 a do 69 D i-[l- (fl-hydroxyethyl) -2-undeeylimidazoline] isophthalate. Tartarie 12. 3 .do a 69 D 1-[1- (B-hydroxyethyl) -2undecylimidazoline] tartarate. Mercaptosucemic 15. 0 do 50 Dl-ll-(fi-hydroxyethyl)-2-undecy1imidazoline] mercaptosuccinate.

A comparison of the anti-static properties of two typical anti-static agents according to the present invention shows their remarkably great anti-static activity in a PVC type resin.

Several phonograph records, comprising Bakelite VYHH, 1% anti-static agent, 1% carbon black and 1% heat stabilizer, produced according to Example 1, are placed in an air-tight chamber at 10% relative humidity. The chamber is fitted with mechanical means for manipulating the phonograph records and other equipment within the air-tight chamber without disturbing the relative humidity. A static detecting head is employed to detect the charge on the surface of the record, and said 5 wherein:

R is a member selected from the group consisting of an alkyl of 7 to 17 carbon atoms, and alkenyl of 7 to 17 carbon atoms, and

R is hydroxy (lower) alkyl, and

(ii) is isophthalic acid. 3. A salt of a member selected from the group consisting of:

(i)' the imidazoline compound of the formula:

%NCH2 11 -0 N-CHz 1' wherein:

6 wherein:

R is a member selected from the group consisting of an alkyl of 7 to 17 carbon atoms, and alkenyl of 7 to 17 carbon atoms, and

R is hydroxy (lower) alkyl, and

(ii) maleic acid.

5. Di[l (,8 hydroxyethyl) 2 undecylimidazoline] adipate.

6. Di[1 (/3 hydroxyethyl) 2 undecylimidazoline] isophthalate.

7. Di[1 (B hydroxyethyl) 2 undecylimidazoline] me-rcaptosuccinate.

8. Di[1 (B hydroxyethyl) -2-undecylimidazoline] maleate.

References Cited by the Examiner UNITED STATES PATENTS 2,267,965 12/ 1941 Wilson 260-309.6 2,659,731 11/1953 Luvisi 260309.6 2,669,546 2/1954 Zussman et al 260-3096 2,761,787 9/1956 Rowe et a1. 10637 2,773,852 12/1956 Rowe et a1 260501 2,773,879 12/ 1956 Sterlin 260-3 09.6 2,778,748 1/1957 R-owe et al 117-138.8 2,917,376 12/195'9 Stromberg et a1. 260-309.6 3,150,147 9/ 1964 Udelhofen 2603O9.6

WALTER A. MODANCE, Primary Examiner.

N. TROUSOF, Assistant Examiner. 

1. A SALT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF: (I) THE IMIDAZOLINE COMPOUND OF THE FORMULA
 2. A SALT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF: (I) THE IMIDAZOLINE COMPOUND OF THE FORMULA
 3. A SALT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF: (I) THE IMIDAZOLINE COMPOUND OF THE FORMULA:
 4. A SALT OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF: (I) THE IMIDAZOLINE COMPOUND OF THE FORMULA: 